Engineering Guide Socket Products

Transcription

1 Engineering Guide Socket Products

2 A comprehensive catalogue of UNBRAKO socket screws and related products In this catalogue you will find complete information about UNBRAKO socket screws and such related products as shoulder screws, dowel pins, pressure plugs and hex keys. Everything you need to select, specify and order these precision products is at your finger tips except actual prices. Furthermore, all data has been organized to let you find the facts you want with the greatest speed and the least effort. Wherever possible, all data for a particular product is presented in a two-page spread for your convenience. This guide refers to products and sizes that may not be manufactured to stock. Please consult an UNBRAKO distributor or UNBRAKO to determine availability. For prices of stock items, see current UNBRAKO fastener price lists or call your local UNBRAKO fastener distributor. For non-stock items, consult your UNBRAKO fastener distributor, or contact the UNBRAKO Engineered Fastener Group by phone at or by fax on or Internet at Commercial and Government Entity (CAGE) Code SFS58 IMPORTANT The Unbrako Engineering Guide is a GUIDE designed to aid product selection, with reference to descriptive and technical data as well as technical discussions for application and use. The use of precision fasteners in the worldwide market has led to the creation of many standards. These standards specify the fastener requirements: dimensions, material, strength levels, inspection etc. Different standards are the responsibility of various organisations and are not always identical. Unbrako supplies precision fasteners manufactured to Unbrako internal specifications, designed to achieve maximum interchangeability with all standards. Reference Consensus standards referred to in the Unbrako Engineering Guide were current at the time of publication. However, Reference Consensus standards are subject to change by any standards organisation at any time. Technical data provided in this guide is for reference only and does not constitute certification that products supplied were manufactured to any specific values. UNBRAKO products are manufactured in accordance with revisions valid at time of manufacture. Unbrako reserves the right to update or modify its manufacturing specifications without prior notice. A direct or indirect reference to a consensus standard to represent that a fastener conforms to particular requirements of the consensus standard shall not be construed as a representation that the fastener meets all the requirements of the consensus standard. The technical discussions referenced in this guide represent typical applications only. The use of information provided is at the sole discretion of the reader. Because applications vary enormously, UNBRAKO does not warrant the scenarios described are appropriate for any specific application. The reader must consider all variables prior to using this information. Products modified other than by UNBRAKO are not guaranteed and not subject to return. LIMITED WARRANTY AND EXCLUSIVE REMEDY Deepak Fasteners Ltd., through its Unbrako Division and associated companies, warrants that these products conform to industry standards specified herein and will be free from defects in materials and workmanship. This warranty is expressly given in lieu of any and all other express or implied warranties, including any implied warranty of merchantability or fitness for a particular purpose, and in lieu of any other obligation on the part of Deepak Fasteners. Deepak Fasteners will at its option, repair or replace free of charge (excluding all shipping and handling costs) any products which have not been subject to misuse, abuse, or modification and which in its sole determination were not manufactured in compliance with the warranty given above. Deepak Fasteners makes no representations or warranties, express or implied, that anything imported, made, used, sold, or otherwise provided under any sale agreement is or will be free from infringement of patents or other proprietary rights of any third persons. Nothing in this application, or any agreement, shall be construed as giving rise to any obligation on Deepak Fasteners part to indemnify or hold harmless any Buyer from any liability relating to Buyer s purchase, use, or re-sale of Deepak Fasteners product, or the incorporation of Deepak Fasteners product into another manufactured product. The remedy provided herein shall be the exclusive remedy for any breach of warranty or any claim arising in any way out of the manufacture, sale or use of these products. In no event shall Deepak Fasteners be liable for consequential, incidental or any other damages of any nature whatsoever except those specifically provided herein for any breach of warranty or any claim arising in any way of the manufacture, sale or use of these products. No other person is authorized by Deepak Fasteners to give any other warranty, written or oral, pertaining to the products. Note:- This is a Live Document and subject to change. Make sure you have the latest version by downloading from

3 TABLE OF CONTENTS UNBRAKO Socket Screw Products Page Quick Selector Guide Inch 2 Socket Head Cap Screws. Alloy Steel and Stainless Steel 4 Low Heads Alloy Steel 11 Shoulder Screws Alloy Steel 12 Flat Head Socket Screws Alloy Steel and Stainless Steel.. 14, 16 Button Head Socket Screws. Alloy Steel and Stainless Steel.. 15, 16 Square Head Set Screws. Knurled Cup Point 17 Socket Set Screws.. Alloy Steel and Stainless Steel.. 18 Pressure Plugs. Dryseal Pressure Plugs.. 24 LEVL-SEAL Pressure Plugs. 25 PTFE/TEFLON * -coated Levl Seal Pressure Plugs 26 Dowel Pins Standard and Pull-Out Type. 28 Hexagon Keys. Short Arm and Long Arm Wrenches 32 Size Selector Table.. 33 Thread Conversion chart. 34 Metric Table of Contents.. 35 Metric Socket Head Cap Screws. 38 Metric Flat Head Cap Screws. 40 Metric Button Head Cap Screws. 41 Metric Shoulder Screws.. 42 Metric Dowel Pins. 43 Metric Socket Set Screws 44 Metric Low Head Cap Screws 46 Metric Hexagon Keys and Size Selector Table.. 47 Metric Tolerances. 48 Metric Conversion Chart.. 50 Technical Section Table of Contents. 51 NOTE: The proper tightening of threaded fasteners can have a signi cant effect on their performance. Many application problems such as self-loosening and fatigue can be minimized by adequate tightening. The recommended seating torques listed in the catalog tables serve as guidelines only. Even when using the recommended seating torques, the induced loads obtained may vary as much as ±25% depending upon the uncontrolled variables such as mating material, lubrication, surface nish, hardness, bolt/joint compliance, etc. LEVL-SEAL, AND UNBRAKO are registered trademarks of Unbrako Group *Reg. Du Pont T.M.

4 PERFORMANCE (See Note 1) tensile 10 7 cycle operating psi dynamic temperatures TYPES APPLICATIONS/FEATURES (room temp.) fatigue (psi) (unplated) page COUNTERBORED PROTRUDING 190,000 20, F Socket Head Cap Screws 1960 Series Alloy Steel 4 10 Use alloy for maximum tensiles; up to 190,000 psi, highest of any socket cap screw 180,000 Socket Head Cap Screws 1960 Series Stainless Steel Use stainless for corrosive, cryogenic or elevated temperature environments, hygienic cleanliness. 95,000 30, F 4 10 Socket Head Cap Screws Low Head Series Use in parts too thin for standard height heads and where clearance is limited 170,000 20, F 11 Shoulder Screws Tool and die industry standards; also replace costly special partsshafts, pivots, clevis pins, guides, trunnion mountings, linkages, etc. heat treat level psi shear strength in psi 160,000 96, F Flat Head Socket Screws Alloy/ Stainless Uniform, controlled 82 underhead angle for maximum flushness and side wall contact; non-slip hex socket prevents marring of material 160,000 96, F 800 F 14, 16 Button Head Cap Screws Alloy/ Stainless Low heads streamline design, use in materials too thin to countersink; also for non-critical loading requiring heat treated screws 160,000 96, F 800 F NOTE 1: Performance data listed are for standard production items only. Non-stock items may vary due to variables in methods of manufacture. It is suggested that the user verify performance on any non-standard parts for critical applications. 2

5 INCH QUICK SELECTOR GUIDE PERFORMANCE (See Note 1) operating temperatures TYPES APPLICATIONS/FEATURES hardness (unplated) page Square Head Set Screws Half-dog or self-locking cup points only. Use where maximum tightening torques are required Rc 45 (min.) 450 F 17 Socket Set Screws Alloy Steel Fasten collars, sheaves, gears, knobs on shafts. Locate machine parts. Cone, half-dog, flat, oval, cup and self-locking cup points standard Rc F Socket Set Screws Stainless Steel Use stainless for corrosive, cryogenic or elevated temperatures environments. Plain cup point standard. Other styles on special order Rb96-Rc F Pressure Plugs 3/4 Taper Dryseal Features common to 3/4 and 7/8 tapers: Dryseal threads for positive seal without sealing compound; controlled chamfer for faster starting Rc Rb 82 Typical 550 F 800 F 400 F Brass 24, 26 7/8 Taper LEVL-SEAL Pressure Plug LEVL-SEAL plug features: controlled 7/8 tape in 3/4 taper hole seats plug level, flush with surface within 1/2 pitch. LEVL-SEAL plug is an UNBRAKO original Rc Rb 82 Typical 550 F 400 F Brass PTFE/ TEFLON** Coated PTFE/TEFLON coated plugs seal at 60% lower seating torques without tape or compound; install faster at lower cost; smaller sizes can be power installed; LEVL-SEAL plug type for 100% flush seating Rc F (uncoated) Hex Keys Tough, ductile, for high torquing; accurate fit in all types socket screws; size marked for quick identity Rc torsional shear in-lb. min. 1.2 to Dowel Pins (Standard) Formed ends, controlled heat treat; close tolerances; standard for die work; also used as bearings, gages, precision parts, etc. core: Rc calculated shear psi surface 8 micro- 150,000 inch (max) Dowel Pins Pull-Out Type For use in blind holes. Easily removed without special tools. Reusable, Save money. No need for knock-out holes. Same physicals, finish, accuracy and tolerances as standard UNBRAKO dowel pins. surface: Rc 60 (min.) 8 micro- 150,000 inch (max) NOTE 1: Performance data listed are for standard production items only. Non-stock items may vary due to variables in methods of manufacture. It is suggested that the user verify performance on any non-standard parts for critical applications. 3

6 SOCKET HEAD CAP SCREWS Why Socket Screws? Why UNBRAKO? The most important reasons for the increasing use of socket head cap screws in industry are safety, reliability and economy. All three reasons are directly traceable to the superior performance of socket screws vs. other fasteners, and that is due to their superior strength and advanced design. Reliability, higher pressures, stresses and speeds in todays machines and equipment demand stronger, more reliable joints and stronger, more reliable fasteners to hold them together. Rising costs make failure and downtime intolerable. Bigger, more complex units break down more frequently despite every effort to prevent it. This is why the reliability of every component has become critical. Components must stay together to function properly, and to keep them together joints must stay tight. Joint reliability and safety with maximum strength and fatigue resistance. UNBRAKO socket cap screws offer this to a greater degree than any other threaded fastener you can purchase off-the-self. UNBRAKO socket cap screws offer resistance to a greater degree than any other threaded fasteners you can purchase off-the-shelf. TENSILE STRENGTH U.S. standard alloy steel socket head cap screws are made to strength levels of 180,000 and 170,000 psi to current industry standards. However, UNBRAKO socket cap screws are consistently maintained at 190,000 and 180,000 psi (depending on screw diameter). The higher tensile strength of UNBRAKO socket screws can be translated into savings. Using fewer socket screws of the same size can achieve the same clamping force in the joint. A joint requiring twelve 1-3/8 Grade 5 hex heads would need only 7 UNBRAKO socket head cap screws. Use them size for size and there are fewer holes to drill and tap and fewer screws to buy and handle. Smaller diameter socket head cap screws vs. larger hex screws cost less to drill and tap, take less energy to drive, and there is also weight saving. The size of the component parts can be reduced since the cylindrical heads of socket screws need less space than hex heads and require no additional wrench space. FATIGUE STRENGTH Joints that are subject to external stress loading are susceptible to fatigue failure. UNBRAKO socket screws have distinct advantages that give you an extra bonus of protection against this hazard. Three major factors account for the greater fatigue resistance of UNBRAKO socket screws design improvements, mechanical properties and closely controlled manufacturing processes. AUSTENITIC STAINLESS STEEL STANDARD SERIES UNBRAKO stainless socket screws are made from austenitic stainless steel. UNBRAKO stainless screws offer excellent resistance to rust and corrosion from acids, organic substances, salt solutions and atmospheres. Superior properties attained with stainless steel include retention of a high percentage of tensile strength and good creep resistance up to 800 F. without scaling or oxidation, and good shock and impact resistance to temperatures as low as 300 F. non-magnetic Valuable in certain electrical applications. Maximum permeability is 1.2 Can be reduced to 1.02 by bright annealing. cleanliness Corrosion resistant characteristics of UNBRAKO screws are useful in chemical, food processing, appliance, paper, textile, packaging and pharmaceutical industries, as well as laboratories, hospitals, etc. eye-appeal Bright, non-tarnishing qualities add to appearance and salability of many products; are valuable assets to designers. Standard processing of UNBRAKO stainless steel socket screws includes a passivation surface treatment which removes any surface contaminations. 4

7 SOCKET HEAD CAP SCREWS Why Socket Screws? Why UNBRAKO Profile of Extra Strength PROFILE OF EXTRA STRENGTH Deep, accurate socket for high torque wrenching. Knurls for easier handling. Marked for easier identification. Head with increased bearing area for greater loading carrying capacity. Precision forged for symmetrical grain flow, maximum strength. Elliptical fillet doubles fatigue life at critical head-shank juncture. 3-R (radiused-root runout) increases fatigue life in this critical head-shank juncture. SHANK ROOT BODY CONVENTIONAL THREAD RUNOUT Note sharp angle at root where high stress concentration soon develops crack which penetrates into body of the screw. UNBRAKO 3-R (RADIUSED ROOT RUNOUT) THREAD Controlled radius of runout root provides a smooth form that distributes stress and increases fatigue life of thread run-out as a much as 300% in certain sizes. Fully formed radiused thread increases fatigue life 100% over flat root thread forms. Controlled heat treatment produces maximum strength without brittleness. Accurate control of socket depth gives more wrench engagement than other screws, permits full tightening without cracking or reaming the socket, yet provides ample metal in the crucial fillet area for maximum head strength. Controlled head forging, uniform grain flow, unbroken flow lines; makes heads stronger; minimizes failure in vital fillet area; adds to fatigue strength. Contour-following flow lines provide extra shear strength in threads, resist stripping and provide high fatigue resistance. The large root radius UNBRAKO socket screw development doubles fatigue life compared to flat root thread forms. 5

8 SOCKET HEAD CAP SCREWS 1960 Series Dimensions Mechanical Properties H 30 T G "LT" THREAD LENGTH UNB A F D APPROX. 45 J LENGTH DIMENSIONS Head markings may vary slightly depending on manufacturing practice. Diamond knurls, UNBRAKO, and UNB are recognized identifications for 1/4 diameter and larger. threads A D G T H J F LT basic per inch nom. screw head diameter body diameter head height fillet diameter size dia. UNRC UNRF max. min. max. min. min. min. max. min. nom. max. min basic # # # # # # # # # / / / / / / / / / * / / / / / / / / / / Performance data listed are for standard production items only. Non-stock items may vary due to variables in methods of manufacture. It is suggested that the user verify performance on any non-standard parts for critical applications. * 1-14 is UNRS (special) standard thread form. 6

9 SOCKET HEAD CAP SCREWS 1960 Series Dimensions Mechanical Properties Application Data NOTES Typical values for test specimens: Material: ASTM A574 alloy steel ASTM F837 stainless steel Dimensions: ANSI/ASME B18.3 Elongation in 2 inches: Hardness: Alloy Steel Rc Reduction of area: Stainless Steel Rb 80 Rc 33 Concentricity: Body to head O.D. within 2% of body diameter T.I.R. or.006 T.I.R. whichever is greater. Body to hex socket (sizes through 1/2 ) within 3% of body diameter T.I.R. or.005 T.I.R. whichever is greater; (sizes over 1/2 within 6% of body diameter). The plane of the bearing surface shall be perpendicular to the axis of the screw within a maximum deviation of 1. For body and grip lengths see pages 8 and 9. Thread Class: #0 through 1 dia. 3A; over 1 dia. 2A. Alloy Steel Stainless Steel 10% min. 10% min. 35% min. 30% min. MECHANICAL PROPERTIES ALLOY STEEL STAINLESS STEEL minimum minimum single recommended seating recommended seat- tensile strength tensile yield shear torque* in-lbs tensile strength ing torque* in-lbs pounds strength strength strength pounds minimum minimum single UNRC UNRF nom. psi psi of body tensile yield shear UNRC UNRF size UNRC UNRF min. min. lbs. min. plain plain UNRC UNRF strength strength strength plain plain # , , ,000 30, # , , ,000 30, # , , ,000 30, # , , ,000 30, #4 1,150 1, , ,000 1, ,000 30, #5 1,510 1, , ,000 1, ,000 30, #6 1,730 1, , ,000 1, ,000 30, #8 2,660 2, , ,000 2, ,330 1,400 95,000 30, #10 3,330 3, , ,000 3, ,660 1,900 95,000 30,000 1, /4 6,050 6, , ,000 5, ,020 3,460 95,000 30,000 2, /16 9,960 11, , ,000 8, ,980 5,510 95,000 30,000 3, /8 14,700 16, , ,000 12, ,360 8,350 95,000 30,000 4, /16 20,200 22, , ,000 17,100 1,200 1,350 10,100 11,300 95,000 30,000 6, /2 27,000 30, , ,000 22,350 1,850 2,150 13,500 15,200 95,000 30,000 8, /16 32,800 36, , ,000 28,300 2,500 2,700 17,300 19,300 95,000 30,000 11, ,050 5/8 40,700 46, , ,000 34,950 3,400 3,820 21,500 24,300 95,000 30,000 13,800 1,270 1,450 3/4 60,200 67, , ,000 47,700 6,000 6,800 31,700 35,400 95,000 30,000 19,850 2,260 2,520 7/8 83,100 91, , ,000 64,000 8,400 9,120 44,000 48,400 95,000 30,000 27,100 3,790 4, , , , ,000 84,800 12,500 13,200 57,600 63,000 95,000 30,000 35,300 5,690 6, , , , ,000 13, /8 137, , , , ,000 14,900 16, /4 175, , , , ,500 25,000 27, /8 208, , , , ,000 33,000 35, /2 253, , , , ,500 43,500 47, /4 342, , , , ,500 71,500 82, , , , , , , , /4 585, , , , , , , /2 720, , , , , , , /4 888,000 1,006, , , , , , ,074,000 1,204, , , , , ,000 *Seating torques for alloy steel calculated in accordance with VDI 2230, Systematic Calculation of High Duty Bolted Joints, to induce approximately 120,000 PSI in the screw threads through inch diameter, and 115,000 PSI over inch diameter. Seating torques for stainless steel are calculated to induce approximately 40,000 PSI stress. Values are for plain screws. For cadmium plated screws, multiply recommended seating torque by.75; for zinc plated screws multiply by See note, page 1. See Technical Guidelines section for additional information on torques, installation, and hole preparation. 7

10 SOCKET HEAD CAP SCREWS 1960 Series Body and Grip Lengths L B L G BODY and GRIP LENGTHS LENGTH LENGTH TOLERANCES up to 1 over 1 to over 2 1/2 diameter incl. 2 1/2 incl. to 6 incl. over 6 #0 thru 3/8 incl /16 to 3/4 incl /8 to 1-1/2 incl over 1 1/ #0 #1 #2 #3 #4 #5 #6 #8 #10 1/4 length L G L B L G L B L G L B L G L B L G L B L G L B L G L B L G L B L G L B L G L B 3/ / / / / / / / / /2 3 3/ /4 4 1/2 4 3/ /4 5 1/2 5 3/ /4 6 1/2 6 3/ /4 7 1/2 7 3/ / /

11 SOCKET HEAD CAP SCREWS 1960 Series Body and Grip Lengths L G is the maximum grip length and is the distance from the bearing surface to the first complete thread. L B is the minimum body length and is the length of the unthreaded cylindrical portion of the shank. Thread length for the sizes up to and including 1 diameter shall be controlled by the grip length and body length as shown in the table. For sizes larger than 1 the minimum complete thread length shall be equal to the basic thread length, and the total thread length including imperfect threads shall be basic thread length plus five pitches. Lengths too short to apply formula shall be threaded to head. Complete threads shall extend within two pitches of the head for lengths above the heavy line on sizes up to and including 5/8 diameter. Larger diameters shall be threaded as close to the head as practicable. Screws of longer lengths than those tabulated shall have a thread length conforming to the formula for sizes larger than 1. 5/16 3/8 7/16 1/2 9/16 5/8 3/4 7/8 1 L G L B L G L B L G L B L G L B L G L B L G L B L G L B L G L B L G L B

12 FEWER HOLES TO DRILL AND TAP three screws do the work of five COMPACT SPACING clearance for socket wrench no wrench clearance necessary old method 5 3/ ,000 psi tensile 85,000 psi yield = 5 x 85,000 x.0775 = 33,000 lbs. max. load UNBRAKO method 3 3/ ,000 psi tensile 170,000 psi yield = 3 x 170,000 x.0775 = 39,000 lbs. max. load old method 12 3/4-16 hexagon head 120,000 psi tensile strength Total strength = 537,000 lbs. UNBRAKO method 16 3/4-16 socket head cap 180,000 psi tensile strength Total strength = 1,074,200 lbs. HIGH TENSILE AND YIELD STRENGTH HIGH SHEAR STRENGTH ordinary bolts socket head cap screws ordinary bolts socket head cap screws old method 120,000 psi. 1/2-20 bolt tensile = 19,200 lbs. yield = 13,600 lbs. UNBRAKO method 190,000 psi 1/2-20 UNBRAKO tensile = 30,400 lbs. yield = 27,200 lbs. Extra UNBRAKO joint strength: tensile 58% increase yield 100% increase old method 120,000 psi. 1/2-20 bolt Shear strength = 14,100 lbs. UNBRAKO method 190,000 psi. 1/2-20 UNBRAKO Shear strength = 22,400 lbs. Extra UNBRAKO shear strength = 8,300 lbs. less wrenching space needed 10

13 LOW HEAD CAP SCREWS SOCKET HEAD CAP SCREWS Low Head Type Smooth, burr-free sockets, uniformly concentric and usable to full depth for correct wrench engagement. Low head height for thin parts and limited space. High strength, precision fasteners for use in parts too thin for standard height socket cap screw and for applications with limited clearances. Fillet under head increases fatigue life of head-to-shank junction. Class 3A rolled threads with radiused root to increase fatigue life of threads by reducing stress concentrations and avoiding sharp corners where failures start. Highest standards of quality, material, manufacture and performance. LENGTH TOLERANCE over 1 over Diameter to 1 to 2 1/2 2 1/2 All UNB W A MECHANICAL PROPERTIES Material: ASTM A574 alloy steel Hardness: Rc Tensile Strength: 170,000 psi min. Yield Strength: 150,000 psi min. NOTE: Performance data listed are for standard production items only. Non-stock items may vary due to variables in methods of manufacture. It is suggested that the user verify performance on any non-standard parts for critical applications. tensile strength lbs. min. single shear strength in threads recommended* (calculated lbs.) nominal seating torque size UNRC UNRF UNRC UNRF inch-lbs #8 2,380 2,500 1,450 1, #10 2,980 3,400 1,700 2, /4 5,410 6,180 3,090 3, /16 8,910 9,870 4,930 6, /8 13,200 14,900 7,450 9, /2 24,100 27,200 13,600 17, DIMENSIONS basic threads per inch A B F H R W nom. screw fillet extension size diameter UNRC UNRF max. min. basic min. max. min. max. min. nom. # # / / / / Thread Length: On all stock lengths the last complete (full form) thread measured with a thread ring gage extends to within two threads of the head. Threads: Threads are Class 3A UNRC and UNRF. *Torque calculated to induce approximately 50,000 psi tensile stress in the screw threads (See Note, page 1). 11

14 SHOULDER SCREWS Dimensions Mechanical Properties Seating Torques Precision hex socket for maximum wrenching strength Knurled head for sure finger grip and fast assembly Neck to allow assembly with minimal chamfering Controlled concentricity between head and body for easier, more accurate assembly Shoulder diameter held to.002 inch tolerance Concentricity controlled between body and thread Finished threads close to body for maximum holding power Head sidewall may have straight knurls at mfrs. option T F 32 I E UNB A K D G J H LENGTH ± APPROX. DIMENSIONS threads nom. per inch A D T H J K G shoulder thread diameter size UNRC max. min. max. min. min. max. min. nom. min. max. min. 1/ / / / / / / / / NOTE: Performance data listed are for standard production items only. Non-stock items may vary due to variables in methods of manufacture. It is suggested that the user verify performance on any non-standard parts for critical applications. 12

15 SHOULDER SCREWS Dimensions Mechanical Properties Seating Torques APPLICATIONS stationary guide moving shaft or pivot pulley shaft uses Shoulder screws have an undercut portion between the thread and shoulder, allowing a close fit. They re used for a wide range of punch and die operations, such as the location and retention of stripper plates, and act as a guide in blanking and forming presses. Other applications for shoulder screws include: bearing pins for swing arms, links and levers, shafts for cam rolls and other rotating parts, pivots, and stud bolts. Shoulder screws are sometimes referred to as stripper bolts, resulting from their use with stripper plates and springs. MECHANICAL PROPERTIES AND SEATING TORQUES single recom.-* E F I T ult. shear mended tensile strength seating thread strength of body torque length max. max..020 lbs. min. lbs. min. inch-lbs ,220 4, ,160 7, ,060 10, ,600 18, ,810 29, ,670 42,410 1, ,680 75,400 3, , ,800 5, , ,500 12, , ,000 16, , ,500 30,000 *See Note, page 1 NOTES Material: ANSI/ASME B18.3,ASTM A574 alloy steel Heat treatment: Rockwell C 36-43; 160,000 psi tensile strength. Dimensions: ANSI/ASME B18.3 Concentricity: Head to body within.005 T.I.R. when checked in V block equal to or longer than body length. Pitch diameter to body within.004 T.I.R. when held in threaded bushing and checked at a distance of 3/16 from shoulder at threaded end. Shoulder must rest against face of shoulder of standard GO ring gage. Bearing surface of head perpendicular to axis of body within 2 maximum deviation. Tensile strength based on minimum neck area G. Shear strength based on shoulder diameter D. Thread class: 3A Screw point chamfer: The point shall be flat or slightly concave, and chamfered. The plane of the point shall be approximately normal to the axis of the screw. The chamfer shall extend slightly below the root of the thread, and the edge between flat and chamfer may be slightly rounded. The included angle of the point should be approximately

16 FLAT HEAD SOCKET SCREWS Dimensions Deep, accurate socket for maximum key engagement Uniform 82 angle under head for maximum contact Fully formed threads for greater strength and precision fit Continuous grain flow throughout the screw for increased strength Heat treated alloy steel for maximum strength without brittleness or decarburization See page 16 for mechanical properties and applications. LENGTH TOLERANCE over 1 over 2 1/2 Diameter to 1 to 2 1/2 to 6 #0 to 3/8 incl /16 to 3/4 incl /8 to 1 incl Dimensions: ANSI/ASME B18.3 Thread Class: 3A H SOCKET DEPTH (GUAGE DIA.) T THREAD LENGTH MAX. -2 IMPERFECT THREADS T SOCKET DEPTH UNB A D G J P F HEAD PROTRUSION LENGTH APPROX. 45 MACHINED SOCKET (MANUFACTURER S OPTION) DIMENSIONS and APPLICATION DATA basic threads A D T G protrusion *** H thd-to-hd P F nom. screw per inch head diameter body diameter gage diameter max. max. protrusion size dia. UNRC UNRF max.* min.** max. min. min. max. min. ref. ref. max. min. max. # # # # # # # # # / / / / / / / / J nom * maximum to theoretical sharp corners ** minimum absolute with A flat *** maximum product length, thread to head NOTE: Performance data listed are for standard production items only. Non-stock items may vary due to variables in methods of manufacture. It is suggested that the user verify performance on any non-standard parts for critical application. 14

17 BUTTON HEAD CAP SCREWS Dimensions Precision hex socket for maximum key engagement Low head height for modern streamline design Fully formed threads rolled under extreme pressure provide greater strength Continuous grain flow makes the whole screw stronger Heat treated alloy steel for maximum strength without brittleness or decarburization See page 16 for mechanical properties and applications. LENGTH TOLERANCE to 1 over 1 Diameter incl. to 2 incl. To 1 incl Over 1 to Dimensions: ANSI/ASME B18.3 Thread Class: 3A SOCKET DEPTH T THREAD LENGTH 2 IMPERFECT THREADS SOCKET DEPTH T UNB A R D J H S F LENGTH APPROX. 45 MACHINED SOCKET (MANUFACTURER S OPTION) DIMENSIONS and APPLICATION DATA basic threads A D T H thd-to-hd S R F J nom. screw per inch head diameter body diameter head height max. fillet dia. size dia. UNRC UNRF max. min. max. min. min. max. min. ref. max. ref. max. min. # # # # # # # # # / / / / /

18 FLAT HEAD AND BUTTON HEAD SOCKET SCREWS Mechanical Properties NOTES Material: ASTM F835 alloy steel ASTM F879 stainless Hardness: Rc for alloy steel Rb 96 Rc 33 for stainless steel Tensile Strength: 160,000 PSI min. ultimate tensile strength for alloy steel 90,000 PSI min. ultimate tensile strength for stainless steel Heat Treatment: Stainless steel is in cold-worked (CW) condition unless otherwise requested. GENERAL NOTE Flat, countersunk head cap screws and button head cap screws are designed and recommended for moderate fastening applications: machine guards, hinges, covers, etc. They are not suggested for use in critical high strength applications where socket head cap screws should be used. MECHANICAL PROPERTIES 16 ALLOY STEEL STAINLESS STEEL ultimate seating torque ultimate tensile seating torque single shear single shear nom. strength lbs. inch-lbs.* strength lbs. inch-lbs.* strength of strength of size UNRC UNRF body lbs. min. UNRC UNRF UNRC UNRF body lbs. min. UNRC UNRF # # # # #4 1,040 1, #5 1,260 1,310 1, #6 1,440 1,620 1, #8 2,220 2,240 2, ,260 1, #10 2,780 3,180 2, ,575 1, /4 5,070 5,790 4, ,862 3,276 1, /16 8,350 9,250 7, ,716 5,220 2, /8 12,400 14,000 10, ,975 7,900 3, /16 16,900 18,900 14, ,570 10,680 4, /2 22,800 25,600 18, ,000 12,770 14,390 6, /16 28,900 32,300 23,900 1,200 1,360 16,300 18,300 8, /8 36,000 40,800 29,450 1,700 1,900 20,300 23,000 10,100 1,060 1,200 3/4 53,200 59,300 42,400 3,000 3,200 30,100 33,600 14,500 1,880 2,100 7/8 73,500 81,000 57,700 5,000 5,400 41,500 45,800 19,700 3,030 3, , ,000 75,400 7,200 7,600 54,500 59,700 25,800 4,550 5,000 *Torques values listed are for plain screws to induce 65,000 psi stress in alloy steel and 30,000 psi tensile stress in stainless steel screw threads. For cadmium plated screws, multiply recommended seating torque by.75; for zinc plated screws multiply by See Note, page 1.

19 SQUARE HEAD SET SCREWS Dimensions Application Data Heat treated alloy steel for maximum strength without brittleness or decarburization Fully formed threads with continuous grain flow for greater strength and precision fit Knurled cup point for positive self-locking and vibration resistance Threads per ANSI B 1.1; Handbook H-28. ANSI B VIBRATIONAL HOLDING POWER vs. SEATING TORQUE Size: 5/16 18x1/2 GREATER TIGHTENING TORQUES of UNBRAKO Square Heads, made of high quality alloy steel, provide 50% more axial holding power than ordinary carbon steel square heads. And, because of the increased torque plus the Knurled Cup Point, UNBRAKO Square Head Set Screws deliver up to 400 percent more Vibrational Holding Power. Seconds VIBRATIONAL HOLDING POWER (Endurance) 400% more Vibrational Holding Power UNBRAKO ALLOY STEEL SQUARE HEADS 200 CARBON STEEL SQUARE HEADS (Plain Cup Point) 0 SEATING TORQUE (Inch Lbs.) DIMENSIONS and APPLICATION DATA SELF-LOCKING KNURLED CUP POINT INTERNAL OR EXTERNAL KNURL FURNISHED AT UNBRAKO OPTION NOTES Material: ASTM A574 alloy steel Heat treatment: Rc 45 min., through heat treated Thread: Class 2A. These torques are appreciably higher than socket set screw torque values, therefore thread stripping strength of mating material must be considered. basic threads A C D F H R W recom.** nom. screw per torque size diameter inch min. max. min. max. min. ±.010 max. min. nom. max. min. inch-lbs. # * * 31/ / / / / / / / / ,350 1/ / ,100 9/ / ,850 5/ / ,250 3/ / ,700 7/ / , / , / / , / / , / / , / / ,000 *#10 may have head dimensions from 1/4 nominal size furnished at Unbrako option. **See Note, page 1. LENGTH TOLERANCE up to 1 1 to 2 2 and Diameter incl. incl. over up to 5/ /4 and over

20 SOCKET SET SCREWS Dimensions Application Data Seating Torques T APPROX. 45 LENGTH TOLERANCE A C and over.63 over 2 Diameter under to 2 to 6 over 6 All ±.01 ±.02 ±.03 ±.06 J APPROX. 30 LENGTH SEE NOTE SEE NOTE** APPROX. 45 APPROX. 45 APPROX. 45 Q C C P 90 C R SEE NOTE** PLAIN CUP FLAT HALF-DOG SEE NOTE 1 CONE SEE NOTE 2 KNURLED CUP OVAL DIMENSIONS basic threads per inch A C P nom. screw size diameter UNRC UNRF max. UNRC UNRF max. min. max. min. # # # # # # # # # / / / / / / / / / / / / / NOTE: Performance data listed are for standard production items only. Non-stock items may vary due to variables in methods of manufacture. It is suggested that the user verify performance on any non-standard parts for critical applications. 18

21 SOCKET SET SCREWS Dimensions Application Data Seating Torques Deep socket Key fits deeply into socket to provide extra wrenching area for tighter tightening without reaming the socket or rounding off corners of key Continuous grain flow Flow lines of rolled threads follow closely the contour of the screw Fully formed threads are rolled, not cut or ground. Metal is compressed, making it extra strong. Threads resist shearing, withstand higher tightening torques Class 3A threads Formed with closest interchangeable fit for maximum crosssection with smooth assembly. Assure better mating of parts Counterbored knurled cup point NOTES Material: ASTM F912 alloy steel ASTM F880 stainless steel Dimensions: ASME/ANSI B18.3 Hardness: Rc (alloy steel only), Rb 96-Rc 33 (stainless steel) Thread class: 3A 1. When length equals nominal diameter or less, included angle is 118. (#4 x 1/8 and #8 x 3/16 also have 118 angle) 2. When length equals nominal diameter or less, included angle is 130. DIMENSIONS RECOMMENDED SEATING TORQUES INCH-LBS.** Q T* J R Applicable only to nominal minimum lengths shown or longer nom. min. min. key max. min. min. nom. basic alloy steel stainless screw length engagement / / / / / / / / / / / / / / / , / ,400 1,700 3/ ,600 3,000 3/ ,000 4,000 7/ ,200 5, ,600 7, / ,600 7, / ,320 9, /4.750 *CAUTION: Values shown in column T are for minimum stock length cup point screws. Screws shorter than nominal minimum length shown do not have sockets deep enough to utilize full key capability which can result in failure of socket, key or mating threads. **See Note, page 1. 19

22 SOCKET SET SCREWS Point Selection According to Application Socket set screws offer three types of holding power: torsional (resistance to rotation); axial (resistance to lateral movement); and vibrational. Size selection is an important factor in holding power. The screw diameter should be roughly 1/2 that of the shaft as a rule-of-thumb. (For more specific size data see pages ) Additional design considerations appear below. Holding power is almost directly proportional to seating torque in a cup, flat, and oval point screws. Holding power can be increased by increasing seating torque. Greater holding power reduces the number of screws required and the assembled cost of the application. By its penetration, the set screw point can add as a much as 15% to total holding power. Cone points, with deepest penetration, give the greatest increase; oval points, with minimum penetration, the least. Making 1 the index for cup point, holding power values from tables on pages 22 and 23 can be multiplied by 1.07 for cone point, 0.92 for flat or dog points, and 0.90 for oval point. Relative hardness between set screw and shaft is also a factor. A 10-point differential between the screw s normal Rockwell C 50 and shaft should be maintained for full holding power. As much as 15% loss in holding power can result from a lower differential. Vibration resistance can be achieved by correct size and proper tightening. The UNBRAKO knurl cup set screw offers additional mechanical locking resistance when required. POINT SELECTION According to Application Point selection is normally determined by the nature of the application materials, their relative hardness, frequency of assembly and re-assembly and other factors. Reviewed here are standard point types, their general features and most frequent areas of application of each type. knurled cup For quick and permanent location of gears, collars, pulleys or knobs on shafts. Exclusive counterclockwise locking knurls resist screw loosening, even in poorly tapped holes. Resists most severe vibration. plain cup Use against hardened shafts, in zinc, die castings and other soft materials where high tightening torques are impractical. 20